Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/41661

Title

Physical and relaxation properties of flame-sprayed ethylene-methacrylic acid copolymer

Author(s)

Brogan, Jeffrey A.;  Berndt, Christopher C.;  Simon, George P.;  Hewtit, David

Abstract

A range of physical and chemical properties of flame-sprayed ethylene-methacrylic acid copolymer (EMAA) were assessed, following different processing conditions. Coatings were produced at a range of specific temperatures by varying the propane flow rate and gun traverse rate. The flame spraying process oxidizes the EMAA copolymer during processing, the extent of oxidation increasing with greater deposition temperatures. Coatings were scanned using dielectric relaxation spectroscopy at a frequency range from 102 to 106 Hz over a temperature interval of -20 to 85°C. The glass transition temperature (usually denoted as the β' relaxation in this system), is attributed to the microBrownian motion of long chain segments in the amorphous phase and is found to decrease with increasing deposit temperature. The oxidation process appears to reduce the position of the β relaxation due to chain scission. The molecular weight for the EMAA powder was reduced from 22,693 g/mol to 9302 g/mol when deposited at 271°C as shown by gel permeation chromatography. Despite the decrease in chain length, the activation energies for β' relaxation increased with increasing coating temperatures. This is attributed to the increased polarity of the oxidized coatings resulting in greater intermolecular association, which outweighs the decreased chain length.

Publication type

Journal article

Source

Polymer Engineering and Science, Vol. 38, no. 11 (Nov 1998), pp. 1873-1881

Publication year

1998

Keyword(s)

Activation energy;  Amorphous materials;  Brownian movement;  Copolymers;  Dielectric relaxation;  Dielectric relaxation spectroscopy;  EMAA;  Ethylene methacrylic acid copolymers;  Flame spraying;  Gel permeation chromatography;  Glass transition;  Molecular structure;  Molecular weight;  Oxidation;  Polyethylenes;  Sprayed coatings

Publisher

John Wiley & Sons

ISSN

0032-3888

Publisher URL

http://dx.doi.org/10.1002/pen.10357

Copyright

Copyright © 1998 (Please consult authors). Publisher does not officially support author/institution self-archiving of either the postprint (final, revised accepted draft) or published version of full text.

Additional information

This work was supported in part by the MRSEC Program of the National Science Foundation under Award Number DMR-9632570, as well as INT 9513462.

Peer reviewed